For aphids, your best bet is a good spray with the hose, rubbing the leaves to smoosh eggs off. Most of the time, they won't make it back up the plant. Then, you can spray if really needed after.

I've only used neem on my potted herbs--mixed success with the aphids. It only affects the ones that get coated.

Are you sure they are aphids and not flea beetles? Eggplant are notorious for attracting flea beetles and it can look pretty bad when the plants are young with leaves that look like Swiss Cheese with hundreds of small pin size holes. Usually the eggplant will grow on and produce without any spraying required.

Yes they are aphids, or at least I think they are. They are a whitish, green color.

I too would hand rub off the aphids and also look for ants that may be herding them. Flea beetles look like specks of black pepper on the leaves and hop like fleas when alarmed.

Agree there is no need to bring out the guns for aphids. Water hose and your fingers are all that is needed. That and cut back on the nitrogen fertilizers since that is what is attracting them.

And there are NO insecticides that are sprayed to prevent pests. You only spray after the pests are there, identified, and then you use the least toxic solution available. Even neem oil can kill beneficial insects when used inappropriately.

<Can anyone recommend other insecticides better than the natria?>

Sure there are all kinds of really big gun toxic pesticides out there that will kill just about anything - including all the good insects - but you sure don't need any of them for aphids.

Dave

A soap spray can be very effective against aphids... I've used one several times for that purpose with great results. You can use any mild liquid soap (such as baby shampoo or mild dish washing liquid) but an insecticidal soap such as Safers is less likely to damage the foliage. It does not take much soap, no more than a teaspoon per quart of water. If you use other soaps, it is best to rinse the plants off with a spray after they have done their work (about 10-15 minutes later). Be sure to spray beneath the leaf canopy as much as possible.

But before spraying any contact killer (organic or otherwise) I would recommend inspecting the plants for beneficial insects or their larvae, which may already have begun feeding on the aphids. If those are present, all you may need is a little patience, and they may reduce the aphid population to tolerable levels within a few weeks. I have a good native population of predators in my area, and most years - if not interfered with - they control the aphids on their own. It is worth keeping in mind that aphid predators multiply much more slowly than the aphids do; so if you kill them accidentally, they may not return... but the aphids, now free of natural predators, will.

You should also be aware that if the aphids are being farmed by ants, it might be necessary to get rid of the ants to prevent them from re-infesting the plants with new aphids. Since ants perform beneficial functions, I only take action against them if the aphids they carry begin to spread disease from plant to plant.